InfoPath Dev

My experience with radio buttons is that they are single select. When I try to insert them, I cannot apply rules for single selection like I can for checkboxes. Say I want an A button and a B button and want the user to select only one or the other, how do I make it so with radio buttons?

When you insert the radio buttons, you can pick how many you want - they are all bound to the same field tho. See attached simple sample, save the file locally, right click and select Design, then preview to try it.